This study received CNS IRB Blue approval on March 17, 2010. The study team is fully staffed and we are actively recruiting patients for this protocol. In July 2011 we received IRB approval for a sub study that broadens the study inclusion criteria up to 5 years since injury. The sub-study will focus on collecting primarily the TBI Common Data Elements (CDEs), bloods, and imagining. In June 2012 the IRB approved expanding our enrollment age range from 18-70, to 18 and older. This same amendment exchanged PET-CT for PET-MRI in the imaging section of the protocol. A section regarding offered treatment was added to address the needs of those subjects who have functional needs with limited access to community resources. At the end of 2014 approval to collect ultra-high field (7 Tesla) imaging parameters was granted by the IRB and the NMR Center allotted time monthly. The 7T magnet has been used to scan both blast and non-blast TBI patients in order to determine if differences between the types of injury can be detected at ultra-high field. In September 2015 the IRB approved expanding our study population with the addition of a healthy volunteer control group. Additionally, we have noted that the local TBI patient population is not normally distributed and has a somewhat higher level of education than average. Although normative data to which results are compared is demographically adjusted, direct comparisons to a control group from the same population will add support to our findings. In earlier versions of the protocol the need for a control group was discussed. However, the decision to hold off on a control group was made until the demographics of the local TBI population was known and healthy controls could be matched to the patient population. Including a control group of healthy volunteers to the data set provides direct comparisons to be made with a normal local sample. Therefore, collecting imaging data on a control group on the identical scanner concurrently with the patient population would provide substantial influence to this research. Collecting the same clinical correlates on a local healthy volunteer sample population, as done in the TBI population, will address this critical need when assessing novel diagnostic imaging and biomarkers techniques. In the case of this study, this control population may need to be matched for a variety of patient demographics as well as any co-morbid illnesses that might affect our imaging or serum results. Additional SLP measures assessing language, discourse, and social cognition have been added to the protocol. Discourse measures will include audio and/or video recording. The discourse analysis is an assessment of language and nonverbal behaviors during procedural, narrative, conversational, and other discourse tasks. Healthy Volunteers are paired with TBI patients of similar age and matching gender, to compare discourse measures between individuals with and without a TBI. Amendments this past year increased enrollment of healthy volunteers and, added Increase flexibility for scheduling and conducting protocol assessments. NIH staff/employees have been added as potential study participants. As per FDA guidance, language was added to reflect precaution regarding contrast agents. Most recently, the addition of 40 Select Exposure participants, who have been identified by a US governmental agency as being exposed to a non-natural energy source, with TBI symptomology was added. Auditory and vestibular testing was also added to the protocol. In addition, 40 unaffected matched Healthy Volunteers will also be enrolled. To date, this study has enrolled 183 TBI patients, approximately 60% of which are enrolled in the prospective cohort study and followed longitudinally, and 26 Healthy Volunteers. Previous recruitment challenges have been addressed with the expansion of a formulized recruitment effort and the opening of communication between the Recruitment Core and the Acute TBI Protocol under Dr. Larry Latour.